US2419935A - Marihuana active compounds - Google Patents

Description

Patented May 6, 1947 No. Drawing; Application. July 9, 1941,

Serial N 0. 401,656

The present application is directed to pharmacological compounds characterized by marihuana activity and the process of preparing the same, and-is. a continuation-in-part of my co-pending application Serial No. 358,306, filed on September 5 'I'hesubject. matter of the present invention may: be illustratedbythe following basic reaction formulas.

= RMg halide CH3 \L .7 ;oo 00 I heoooztm- A oooctnr (.ILB)

27 Claims. (01. 260- 333) ClHo c0 Q00 caHs A OOOGaHs coo-cine In Formula I-A above R1 represents hydrogen. In the other formulas (I B to ID) R1 repre sents a lower alkyl group which as shown in Formula I may be attached to either of the 3, 4, 5or 6 positions.

Formula II above represents a 1,3-dihydroxy- 5-alkyl benzene of which the 5-methyl-(orcinol) and S-n-amyl-(olivetol) are typical. examples. Other examples where R2" represents the following alkyl groups are the methyl, ethyl, propyl; bufiyl, n-amyl', iso-amyl, hexyl, heptyl, 4-methyl-hexyl, 3-ethyl-amy1, octyl', nonyl and decyl derivatives. These compounds may be prepared by known processes (J. A. 0. 3., 61, 232); the preparation of the 1,3-dihydroxy-S-n-octylbenzene described in my co-pending pulegone condensation application, Serial No. 401,655, being illustrative.

In the preparation of the'compounds of the present invention a cycloheXan0ne-2-carboxylate I is first condensed with a 1,3-dihydroxy-5-alkyl benzene II to form a dibenzopyrone III. The benzopyrone is then reacted with a Grignard reagent'to form the desired dibenzopyran IV. The following examples will serve to illustrate the present invention.

Example I 1-hydroxy-3-n-amyl-6,6,9 trimethyl 7,8 9,10- tetrahydro-S-dibenzopyran.

A- solution of about 2% grams of 1,3-dihydroxyfi-mamylbenzene- (olivetol), 24' grams of ethyl 5- methyl-cyclohexanone 2 carboxyl'atefi and" 16 grams of phosphorus oxychloride in 1800. c.'of dry benzene is first refluxed for about seven hours. After' completion of the refluxing} the reaction mixture is first Washed with dilute aqueous sodium bicarbonate and is thenwashedrwith water. The benzene layer is then separated in theusual manner, the benzene evaporatedand the residue .(1- hyd roxy 3-n-amyl-9 m'eth'yl 'Z,8, 9,l0"-"tetrahy'- dro fi-dibenzopyrone) after purification byr'e crystallization from ethyl acetate, is obtained'a's' white needles with a melting. point of 180-181 C. If desired, the crude residue after crystallization from methanol may be converted to the pyran as described below.

A suspension of about 9 grams of I-hydroxy- 3 3 n amyl -9- methyl -7,8,9,ltetrahydro-fi-dibenzopyrone in 140 c. c. of solvent made up of about 3 parts of dry benzene and 1 part of dry di-n-butyl ether is next mixed with a solution Grignard reagent made up from about 9 grams of magnesium and 22.5 cc. of methyl iodide in '75 c. c. of dry ether and the total mixture then refluxed for about eight hours. After refluxing the reactipirmixtpre is poured'onto"iced ammo accordance with the general process of Example I by refluxing for four hours about 6 grams of ethyl 4-methyl-cyclohexanone-2-carboxylate and 1,3-dihydroxy-5-n-amy1-benzene in about 55 cc. of dry benzene containing 4.8 grams of phosphorus oxychloride. After treating with excess aqueous sodium bicarbonate, cooling, washing with water and benzene and crystallization from methanolthepyrone prcdu ct'is'obtained'as White nium chloride sclution the organiclayer sep 1o crystals with an ielting pointof-169 1695 C.

arated, the aqueous layer extracted once with benzene and the combined benzene solutions? The desired pyran derivative may be prepared by reacting the pyrone intermediate with the washed successively with water dilute aqueous ,proper al1ylfirignard reagent in accordance with sodium bicarbonate and water.

residue dissolved or taken up in ab9ut 1 50 c. c.

is then boiled on a hot: plate for about thirty minutes While maintaining the volume substantially constant by addition of more solvent as necessary. 'Attergseparation of thereaction solution, e. g;; {1y decantation, from: a smallaamount of insolubleimateirial, the solvent iseyaporated in the usual manner and'theresidua' l-hydroxy- 3-n-amyl-6, ,9- trimethyl 7,8,9,10-. tetrahydro-6- dibenzopyran distilled. This product is obtained asaaiviscous.oil,..B.., R. 71751 180. (1. (0,0 2 mrn ljath1te'mpeiaEIreJQ5 -2001QJJLZZQ QLSQBZ; "o tandingjitisolidifle andiln m cg ur i .by rc'ryst'allizatioiijfrom glacial'acetica d;

white crystals with" a melting point '12f. 7.3.".. C. p

l l zcmpl ll =hydroxy+3'-n-;-amyl-fifiediethylelk methyl-7;8,- 9,10 tetrahydro fi-dibenzopyram; r. *1;- .IBy'followin 'thetgeneral process ofExamD I except for .the-us eoi an'ethyl ,Grignard reagent .(e; g; ethyl magnesium bromide) the'cfiediethyl derivative may be-xobtained-having: a;-;B. 1?; of about 1855495? C. bath"200-2-10f;C.;).

-l3yfollowingthe general proeessot Example;

xc p 1 use i l. .G i ne rr i lei-g, npropyl magnesium bromide) the 6, 6di;n propyl derivative may be obtained-as a redresin having a 13.; P, of about -200f.l" C.; (2 -mm.,f-bath 1-hydroxy-3-n-amyla'7;8;9;10-tetrahydro-G-dibenzopyrone. Thispyrone intermediatemay-be'prepared in accordance with the general process of Example I by condensing ethyl cyclohexa'none z carboxylate W'ith"1,3 dihydroxy 5 n' arnylbenzene. Upon purification itifor'ms white crystals with a melting point-of'183183.5 C." f

JThe desired pyran derivative maybeprepared by' reacting the'tpy'rone intermediate with "the proper alkyl' Grignard reagent in accordance with thefabove examples.- By using a'methyl Grignard reagent in accordancewith: Example I the I-hydroxy'-'3-n=am'yl-6; 6-'dimethyl-.-'7,8, 9, IO-tetrahy drd-.6-'dib enzopyran is' obtained 'as' --a viscous 'oil With' a B;'P."0f"l75180 C;"(0.02 mm; bath 195-200C.); 1. 1 i

1 1 Eimmple V lghydroxy-3 n amyl=8 =methyl 7,8,9,l0tetrahy dro-G-dibenzopyron."' J j Thi r ro e n m d ate,m ybeprepared in of petroleum ether (B. P. (so-100 0.) 2x51 5195 drops of 48 per cent aqueous hydrobromic acidis next added to the petroleum ether solutiorrwhieh;

Theorganic so the above examples. vent (benzene, etc.) is then evaporated andthe 5 -5 l -hydroxy -K n-heptyl-9-methyl-'7,8,9,l0-tetra- Example VI tibd'ihe'itstitanium-172 173 c.-

The desired pyran may be prepared by -reactil the I pyrone "intermediate with the proper ialkyl Gi'lgh ard feag1t'-'ih--accordance ivith'thel'a "v examples. By using the methyl Grigfirdiagent in accordance with Example I the .1-hydroxy-3-n-heptyl-6,6,9-trimethyl -7,8,9,l0- tetrahydro-G-dibenzopyran isobtained with a .BQHP. of about 225 -22s-c. (c.05 min);

EwampYET/H. M 1-hydr0xy-3-n-hexyl-6,6,9-alkyl-7,8,9,IO-tetra hydro-G-dibenzopyran.

The pyrone intermediate. for these products may beprepared by condensing 1*,35dihydroxyhexanone-2-carb'oxy1ate in,raccordance with the above examples. By using ethyl 5emethyl-cycloheXanone-2-carboxylate a pyrone product is obtained with a melting point of about 173-174 C.

The pyran products may also be prepared in accordance with the above examples by reacting the pyrone with the proper alkyl Grignard reagent. By using the methyl Grignard reagent and the:Q-methyI-pyronepmduct a l-hydroxy- 3-n-hexyl-6,6;9etrimethyl 7,8,9,10-tetrahydro-6- dibenzopyran is obtained with a B. P. of about 190-192 C. (1 mm). This product is of particular interest as it has been found to be over er en -me e a ti t eme? c on n m l e fiva ve f xam lly liefiin-h x W) m le' lh s r e lby: lowin formula: v H I.

Eacaznp le VIII I 1-hydroXy-3-n-amyl 10-methy1-7,8,9,10-tetrahydro-G-dibenzopyrone.

A mixture'of about2 grams of ethyl G-methylcyclohexanone-2-carboxylate; 2 grams of 1,3-dihydroxy-5-n-amyl benzene; 1.75 rams of phosphorus oxychloride; 5 cc. of benzene and 15 cc.

.5. of toluene was refluxedfor about 12 hours. -'It was then" poured into excess saturated aqueous sodium carbonate solution and boiled until the solvent was removed. On cooling, the product was filtered and washed with benzene. White crystals purified from. a mixture of methanol and isopropanol :have a melting point of about 1944194,.5" C. 1

The l-hydroxy 3 n-amyl 6,6,,10 trimethyl- 7,8,9,10-tetrahydro-6-dibenzopyran formed from the above pyrone in accordance with processes outlined above has a B. P. of about l8l-185 C. at 0.5-1.0 mm. (bath 214-218 0.).

Additional examples prepared in accordance with the general processes outlined above are the 1- hydroxy-3-n-propyl 6,6,9-trimethy1- 7,8,9,10- tetra-hydro-fi-dibenzopyran' (B. P. 185 0., 2 mm.) 1-hydroXy-3 n butyl 6,6,9 trimethyl- 7,8,9,10-tetrahyclro-6-dibenzopyran (B. P. 178- 180 C., 1 mm); 1-hydroxy-3-n-octyl-6,6,9-trimethyl '7,8,9,l0 tetrahydro-G-dibenzopyran (B. E.;, 2l5.220,C., 0.01 mm), etc. Other pyran products, coming within the scope of the. present invention maybe prepared by condensing the proper, alkylated-cyclohexanone 2 carboxylate withthe proper 1,3dihydroXy--alkylated benzene and reacting the pyrone product obtained with the proper alkyl-magnesium-halide in accordance with the above exam les. The compound of Example 1 has the same .empirical formula as the compound given the same name in my co-pending application, Serial Number 440,971. The difference therefrom is that, because it is synthetically derivedfrom materials other than charas, it is definitely free of even chemical traces of nonacosane and certain terpenes and other'contaminants' found in products derived from hemp. It also may difier with respect to the position of the labile bonds in the all-carbon rings.

The products of the present invention form at the 1-position themonoacyl and monoalkyl ether derive,tives. Upon reduction with one mole equivalent of-hydrogen the double bond in the lefthand ring is eliminated and the correspondinghegtahydro analogs are produced. These hexahydro products differ from the hexahydrocannabinolsynthesized from cannabidiol by isomerizat ionhiollowed, by reduction, in that they are optically inactive. "The pyran products of the present invention differ from the pyran products prepared from cannabidiol in the position of the double bond in the lefthand ringand from the pulegone. condensation pyrans described in my copending application Serial No. 401,655 in that they are also optically inactive. The tetrahydro cannabinols prepared from cannabidiol by acidic isomerizing agents are described in my (toing" application Serial No. 352,931. Using very dilute 'ethanolic hydrochloric acid as the isomeriziri'g agent a low rotating tetrahydrocannabinol an-130:9 is produced, while using isomerizing agents such as p-toluene-sulfonie acid in benzeneor a drop of sulfuric acid (100%) in cycylohexane .a high rotating tetrahydrocannabinol d"D-265:5 is produced. These products while optically active diifer from the pulegone condensatiorr pyrans in the position of the double bond on the-lefth-and ring.

The lower alkyl ethers (e. g., methyl, ethyl, etc.) and lower acyl derivatives -(e. g., acetate, propion-ate, etc.) may be prepared in accordance with standard practices such as the processes described in my co-pending application Serial No, 352,931. :The h'ekahydro products may also be preparedby reducing the tetrahydre products in hydro Formula A corresponds to Formula B as illustrated below: 1

It will also be understood where R1 islan alkyl group, that the alkyl group replaces one of the Hatoms shown ,inFormula B.

The products of tho present invention have utility in the therapeutic field as, for example, in the treatment of dope addicts and alcoholics. A specific use is to eliminate or ameliorate the withdrawal symptoms experienced in the treatment of opiate derivative addictions.

It will be obvious to those skilled in the art that the present invention is not limited to the illustrative examples described above. All modific.a-' tions of the present inventionare intended to be covered by the claims annexed hereto.

l. The process of preparing a tetrahydrodibe'm zopyran which includes the following steps: (a) condensing an R1-cyclohexanone-2-carboxylate with a 1,3-dihydroxy 5-RzCHz-benzene and (b) treating the pyrone reaction product formed by step (a) with an R-Grignard reagent toform the corresponding tetrahydro-G-dibenzopyran, where R1 represents a member selected from the group consisting of hydrogen and lower alkyl groups, R2 represents a member selected from the group consisting of hydrogen and alkyl groups having 1-10 carbon atoms and R represents a lower alkyl group.

2. The process of preparing a tetrahydrodibenzopyran which includes the following steps; (a) condensing a lower alkyl-cyclohexanone '2 carboxylate with a 1,3-dibydroxy 5-R2CH2-benacne and (b) treating the pyrone reaction prodnot formed by step (a) with a lower alkyl-magnesium halide to form the corresponding tetrahydro-G-dibenzopyr-an, where R2 represents a 'member selected from the group consisting of hydrogen and alkyl groups having 'l-10 carbon atoms.

3. The process of preparing a tetrahydrodibenzopyran which includes the following essential steps: (a) condensing a lower alkyl-cyclohexanone-2-carboxylate with a 1,3-dihydroXy-5- amylbenzene and (b) treating the pyrone reaction product formed by step (a) with a lower alkyl magnesium halide to form the: corresponding tetrahydro-6-dibenzopyran.

4. The process of preparing a tetrahydrodibenzopyran which includes the following essential steps: (a) condensing a lower alkyl-cyclohexanone-2-carboxylate with a 1,3-dihydroxY-5- hexylbenzene and (b) treating the pyrone reaction product formed by step (a) with a lower alkyl magnesium halide to form'the corresponding tetrahydro-6-dibenzopyran.

5.. The process of preparing a tetrahydrodibenzopyran which includes the following essential steps: (a) condensing a lower alkyl-cyclohe'xanone-Z-carboxylate with a l,3-dihydroxy-5- alkyl magnesium halide to forrnl the correspond+j ing tetrahydro fi-dibenzopyrari. v

6..The process of preparing a". tetrahydrodibenzopyran which includes the following essentiahsteps: (a) condensing a 5-methyl-cyclohex-' anone-Z-carboxylate with 1,3-dihydroxy-5-n"- h'exylbenzene, and (b) treating the reaction product of step (a) with methyl magnesium halide to form 1-hydroxy-3-n-hexyl-6,6,9-trimethyl-'7,8,9, l-tetrahydro-6-dibenzopyran.

'7. The process of preparing a tetrahydrodibenzopyran which includes the following essential steps: (a) condensing a -methyl-cyclohexanone-Z-carboxylate with 1,3-dihydroxy-5-nhe'ptylbenz'ene, and (17) treating'the reaction product of step (a) 'with methyl magnesium halide to form l-hydroxy-3- n-heptyl-6,6,9 -trimethyl-7,8,9,lfl-tetrahydro-fi-dibenzopyran.

8, In the preparation of a tetrahydro-dibenzopyran, the process which includes the following steps: (a) condensing a'cycIoheXanOne Z-carboxylate with a' 1,3-dihydroxy 5-alkylbenzene in the presence of phosphorus oxychloride to form the corresponding dibenzopyrone intermediate, andlb) treating the pyrone intermediate with a lower 'alkyl Grignard reagent to form the corresponding dibenzopyran. s

9. A tetrahydro-dibenzopyran product represented by the following formula:

where R1 represents a member selected from the group. consisting of hydrogen and lower alkyl groups, R2 represents a member selected from the group consisting of hydrogen and ,alkyl groups having 1- 10 carbon atoms, R represents lower alkyl groups and Y is selected from the group consisting of hydrogen and lower alkyl and acyl groups; said product being substantially free of cannabidiol and of toxic impurities, and optically in ive- .7 A A 10. A productrepresentedby the formula of; claim 9 in which R2 is a butyl group. 11. A tetrahydro-dibenzopyran product represented by the following formula: y

where R1 represents a member selected from the group consisting of hydrogen and lower alkyl groups, R represents lowe'r'alkyl groups and Y is selected from the group consisting 'of hydrogen and lower alkyl and acyl groups.

-12; A product represented by'the; formula" of claim 9'in which R2 is 'a hexyl group;

13. A product represented by the formula ofc1aim9 in which R1 is a'lower alkyl 8130111351: ia-a n-butyl group and Yxis hydrogen. v 14: A- product represented by the formula.- Jo! claim 11 in which R1 is a lower alkyl group, the C5H11 is a n-amyl group, and Y is hydrogen; 153A product represented by the formula-o1 claim 9 in which R1 is a lower alkyl grouprRa is an-hexyl group andYis hydrogen. 1' 16. A tetrahydro-dibenzopyran product repre sented by the following formula:

inwhich R represents lower alkylgroups. I w

191 Aproductrepresnted by the formula of claim 16 in which R2 is a hexyl group.

20, The product 1-hydroxy-3-n-amyl-6,6,9tri methyl-7,8,9,lQ-tetrahydro-G-dibenzopyran; said product being substantially free of cannabidlol and of'toxic impurities, and optically inactive.

21. The product, l-hydroxy-3-n-hexyl-6,6,9- trimethyl-7, 8, 9, 10-tetrahydro-6-dibenzopyran.

22. A product represented by the formula of claim 16 in which the Rs represent methyl groups and R2 a n-hexyl roup. v H 3. chemical intermediates useful in organic synthesis, tetrahydrodibenzopyrones havingall four extra hydrogens on the same all-carbonring remotefromjthe oxygen of thepyronering. .24. As chemical intermediates ,useful in organic synthesis, dibenzopyrone substituted in 1 position by a grouprselected from the ,class hydroxy, acyloxyvand alkoxy; substituted in 3 position by a groupLCI-IzRlin whichR is selected from the class allgyl having from onetoten carbon atoms; substituted once in the all-carbon ring remote from the. oxygen of the pyrone ring by methyl in a, position selected from' the 'class, 8, 9,10.

25; As a chemical intermediate useful in organic synthesis, 1-hydroxy-3-n-amyl-9 -inethyl- 7,8, l @t a r6-d b n pyrqn 26. Asa chemical intermediate useful, in gore n c syn i lrhy r -n-he y -9-methy 'Z,8,9,1 0-tetrahydro-fi dibenzopyrone. no-

27, {The process of preparing atetrahydrondle benzopyran which includes the following essenttal 9 steps: (a) condensing a B-methyI-cyglohexanone- Z-carboxylate with 1,3-dihydroxy-5-n-amylbenzene, and (b) treating the reaction product of step (a) with methyl magnesium halide to form 1-hydroxy-3-n-amyl 6,6,9 trimethyl 7,8,9,10- tetrahydro-B-dibenzopyran.

ROGER ADAMS.

REFERENCE S CITED The following references are of record in the file of this patent:

FOREIGN PATENTS Country Date Germany July 12, 1915 Number OTHER REFERENCES